How to sort listview with remote data instantly using Comparator in Android?

Question

When I click a button to sort the listview, it works but only if I start scrolling the listview does it show the sort order.

This is what I have in my data model class:

    public static Comparator<Emplyoyee> sortNameAtoZ = new Comparator<Emplyoyee>() {

        @Override
        public int compare(Emplyoyee lhs, Emplyoyee rhs) {
            String emp1 = lhs.getName();
            String emp2 = rhs.getName();

            return emp1.compareTo(emp2);
            //descending order
            //return StudentName2.compareTo(StudentName1);
        }};

When the user clicks the button, I call this:

Collections.sort(rowdata, EmployeeRowData.sortNameZtoA);
adapter.notifyDataSetChanged();

After doing the research and comparing different sources, the setup is the same as it is here but it is not sorting the listview instantly upon clicking the button. I'm populating the listview with data from a remote database using Volley.

KDeogharkar · Accepted Answer · 2016-05-14 06:54:47Z

2

Reset your arraylist.

try this:

Collections.sort(rowdata, EmployeeRowData.sortNameZtoA);

    adapter.setArrayList(rowdata);

    adapter.notifyDataSetChanged();

Your adaptor

public void setArrayList(ArrayList<Emplyoyee> array){
yourArray =array;
}

edited May 14, 2016 at 6:54

answered May 14, 2016 at 6:36

KDeogharkar

10.9k7 gold badges53 silver badges97 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Steve C. Over a year ago

The first part goes in the buttons' onClick method correct?

Steve C. Over a year ago

Tried adding the first part to my buttons' onClick and it gives the error "incompatible types" . Required=ArrayList, Found=Void. I have it written exactly as you do.

Steve C. Over a year ago

if it helps, EmployeeRowData is the data model. Not sure if that makes a difference. Thats not the adapter.

Steve C. Over a year ago

Works perfectly! Thank you. I guess resetting the ArrayList using setArrayList is what was needed.

AJW Over a year ago

@KDeogharkar A commenter (elBradford, see here: stackoverflow.com/questions/9906464/…) mentioned that "The .sort function automatically calls notifyDataSetChanged, so if you use this code with the built-in sort, you'll get into an infinite loop and overflow your stack." So is your line "adapter.notifyDataSetChanged();" needed above or can it be safely removed?

Collectives™ on Stack Overflow

How to sort listview with remote data instantly using Comparator in Android?

1 Answer 1

5 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related